The process isn't that interesting to be honest. I just used a crossword solver to find all the English words ending with "sh" and then Googled them to see if projects already existed.

Then I Googled different types of shells in nature to look for something that sounded interesting. That's where 'murex' came up, it's a genus of a sea snails and it also loosely followed the UNIX naming convention (Linux / Unix / Minix / etc).

I guess I could have just made a word up rather than trying to be clever :)

I like the name 'murex'. The first thing it makes me think of is murex shells - as in the sea snail - which we used to find on the beach all the time when I was a kid. And as you say the 'X' at the end conjures up Unix.

Ah, that's nice!